1. Field of the Invention
The present invention relates to liquid treatment of a substrate such as a semiconductor wafer or the like, in particular to a liquid treatment system using a plurality of liquid treatment units and a liquid treatment method therefor.
2. Description of the Related Art
When forming a metal layer on a surface of a substrate such as a semiconductor wafer or the like, a liquid treatment method such as a plating method or the like is employed.
When forming a metal layer by means of a plating method, a bath accommodating a plating solution is necessary.
With the increase of structural complexity in semiconductor elements, semiconductor wafers have frequently been plated with a plurality of plating solutions of different compositions, resulting in an increase in the number of plating solution baths being used.
Furthermore, in order to treat a large number of semiconductor wafers at a time to reduce manufacturing cost, the number of plating solution baths being disposed in a treatment chamber increases.
However, when many plating solution baths are employed the area occupied by the equipment increases and the utility and efficiency of the site decreases.
Furthermore, mist containing the plating solution diffuses from the plating solution bath to contaminate the inside of the treatment chamber, thereby possibly deteriorating the quality of the metal layer.
Still furthermore, when plating solution baths of different compositions are adjacently disposed, one plating solution is likely to enter from one bath into another one.
An aspect of the present invention is to provide a liquid treatment system that uses a lot of area efficiently.
Another aspect of the present invention is to provide a liquid treatment system capable of separately controlling an atmosphere of the liquid treatment system or each liquid treatment unit, and a liquid treatment method therefor.
Still another aspect of the present invention is to provide a liquid treatment system capable of densely disposing liquid treatment units that use different kinds of treatment solutions.
(1) In an embodiment of the present invention, the liquid treatment system involving comprises
a first liquid treatment unit constructed and arranged to implement a first liquid treatment with a first treatment solution containing a metal ion on a substrate,
a second liquid treatment unit constructed and arranged to implement a second liquid treatment on the substrate thereon, after the first liquid treatment is implemented, and
a first transfer unit constructed and arranged to transfer the substrate in a vertical direction,
wherein the first and second liquid treatment units are disposed in multi-tiers in a vertical direction around the first transfer unit.
Due to the multi-tier disposition of the first and second liquid treatment units, an occupation area of the liquid treatment system can be rendered smaller.
In one embodiment, the first liquid treatment unit may implement the first liquid treatment on a first surface of the substrate and the second liquid treatment unit may implement the second liquid treatment on a second surface of the substrate. In addition to the above, the first transfer unit may have a mechanism constructed and arranged to turn upside down surfaces of the substrate.
The first and second liquid treatment units can treat both surfaces of the substrate simultaneously. Accordingly, treatment efficiency can be improved. Furthermore, when the first transfer unit has a mechanism for turning upside down the substrate, it is not necessary to dispose the reversal mechanism separately. Furthermore, the reversal of the substrate is facilitated during the transfer when the first transfer unit has the mechanism for turning upside down the substrate.
In another embodiment, the liquid treatment system may further comprise a first gas feed constructed and arranged to feed a cleansed gas in the liquid treatment system,
The second liquid treatment unit may be disposed on an upstream side of the flow of cleansed gas relative to the first liquid treatment unit.
Accordingly, an atmosphere on the second liquid treatment side can be maintained clean.
The liquid treatment system may further comprise a second transfer unit constructed and arranged to transfer the substrate out of the second liquid treatment unit.
The substrate treated by the second liquid treatment unit is transferred outside the second liquid treatment unit with the use of the second transfer unit. Accordingly, the first transfer unit is prevented from touching the substrate treated by the second liquid treatment unit.
The second liquid treatment unit may be disposed above the first liquid treatment unit.
For instance, a cleaning unit as the second liquid treatment unit is disposed above a plating unit as the first liquid treatment unit. As a result, the second liquid treatment unit is prevented from being contaminated by an atmosphere of the first liquid treatment unit.
The liquid treatment system may further comprise a heating unit for heating the substrate after the first liquid treatment is applied.
For example, with the use of the heating unit, heating such as annealing for reforming a copper plating layer formed on the substrate can be implemented.
The liquid treatment system may further comprise a temperature controller constructed and arranged to control a temperature in the liquid treatment system.
By suppressing a temperature rise in the liquid treatment system, mist that may be generated from the treatment solution can be reduced.
The first and second liquid treatment units are units independent from each other and detachable from the liquid treatment system.
Since the first and second liquid treatment units are detachable from the liquid treatment system, maintenance is facilitated and maintenance efficiency can be improved. Furthermore, since the first and second liquid treatment units are independent from each other each can be easily replaced when needed.
The first liquid treatment unit may have a housing capable of maintaining an interior atmosphere thereof substantially airtight.
Thereby, the mist of the treatment solution is prevented from flowing out of the first liquid treatment unit to contaminate an exterior atmosphere of the first liquid treatment unit.
The first liquid treatment unit may further comprise a second gas feed constructed and arranged to feed a cleansed gas in the housing.
By the use of the second gas feed, a clean atmosphere can be maintained in an interior of the first liquid treatment unit.
The first liquid treatment unit may further comprise an exhaust arranged to make a pressure of the housing interior lower than that of the housing exterior.
When sending the substrate in and out of the housing, contaminated air can be prevented from flowing outside the liquid treatment unit.
The first liquid treatment unit may further comprise a temperature control means for controlling a temperature in the housing.
By suppressing a temperature rise in the liquid treatment unit, the generation of mist from the treatment solution can be reduced.
The interior of the housing may be partitioned in two portions. A first treatment portion including a transfer position for transferring in and out the substrate, and a second treatment portion including a liquid treatment position for implementing the first liquid treatment on the substrate.
The first liquid treatment that is likely to generate the mist of the treatment solution is carried out in the second treatment portion. Furthermore, since the substrate is sent in and out in the first treatment portion, it is preferable to implement the transfer in a cleaner atmosphere. Thus, by partitioning the interior of the housing according to cleanliness, when sending the substrate in and out of the first treatment portion, the mist of the treatment solution can be prevented from flowing out.
The first and second treatment portions may include, respectively, a cleaning position for cleaning the substrate and a spin dry position for spinning the substrate to throw off a first cleaning fluid.
(2) Another aspect of the present invention is to provide a liquid treatment method, the method comprising:
implementing a first liquid treatment on a substrate by means of a first liquid treatment unit accommodating a first treatment solution containing a metal ion,
cleaning with water in the first liquid treatment unit, the substrate after the first liquid treatment is implemented,
transferring the cleansed substrate, together with adsorbed moisture, by means of a transfer unit, to a second liquid treatment unit, and
implementing a second liquid treatment, by means of the second liquid treatment unit, on the transferred substrate.
A component of the first treatment solution on the substrate dries during the transfer to prevent particles from forming on the substrate.
(3) Another aspect of the present invention is to provide a liquid treatment method, the method comprising:
implementing a first liquid treatment on a first surface of a substrate by means of a first liquid treatment unit accommodating a first treatment solution containing a metal ion,
turning during transfer to a second liquid treatment equipment by means of a transfer unit, upside down front and back surfaces of the substrate on which the first liquid treatment is implemented on the first surface, and
implementing, by means of the second liquid treatment unit, a second liquid treatment on a second surface of the substrate of which front and back surfaces are turned upside down.
The substrate is turned upside down during the transfer from the first liquid treatment unit to the second liquid treatment unit. Accordingly, the first and second liquid treatment can be efficiently implemented on the first and second surfaces of the substrate.